Synthesis Of Methyl Tert-butyl Ether Research Articles

Synthesis of Methyl tert-Butyl Ether Catalyzed by Acidic Ion-Exchange Resins. Influence of the Proton Activity

The catalytic activity of various strong acid ion-exchange resins on the synthesis of methyl tert-butyl ether (MtBE) from methanol and isobutene has been investigated. Relative to Amberlyst 15, Kastel CS 381 and Amberlyst CSP have similar rate constants, whereas Duolite ES 276 and Amberlyst XE 307 have significantly higher and Duolite C26 and Duolite C16P substantially lower rate constants. All resins show a great decrease in catalytic activity if part of the protons is exchanged by sodium ions. At 10% proton capacity the rate constants per equivalent acid are reduced by a factor of 9 (for Amberlyst XE 307 and Kastel CS 381) to more than a factor 20 for Amberlyst 15 and Duolite ES 276, resulting in 100-200 times lower MtBE production rates. Depending on the catalyst applied, mass transfer limitations start to occur between 50 and 80 degrees C. Values of the effective diffusion coefficient of isobutene varied between 0.4 x 10(-9) and 4.1 x 10(-9) m(2) s(-1) at 80 degrees C.

Catalysis by hetropoly compounds. Part XXVI . Gas phase synthesis of methyl tert-butyl ether over heteropolyacids

Gas phase synthesis of methyl tert-butyl ether (MTBE) from methanol and isobutylene has been studied with several heteropolyacids at 303–383 K. It was found that a Dawson-type heteropolyacid, H 6P 2W 18O 62, was much active than Keggin-type heteropolyacids, H n XW 12O 40 (X = P, Si, Ge, B, and Co), and other solid acids such as SO 2− 4 ZrO 2 , SiOAl 2O 3 and H-ZSM-5 at 323 K. Since the acid strength of H 6P 2W 18O 62 was weaker than H 3PW 12O 40 and H 4SiW 12O 40, factors other than the acid strength are important for the catalytic activity. Pseudoliquid phase behavior was demonstrated for H 6P 2W 18O 62 and H 3PW 12O 40 by the measurements of the absorption of methanol during the reaction and by the unique pressure dependencies of the rate of synthesis. From the absorption data (the amount and rate), it is concluded that the high catalytic activity of H 6P 2W 18O 62 is brought about by a high-activity state of the pseudoliquid phase in which controlled amounts of molecule are absorbed and the absorption-desorption is rapid. On the other hand, the pseudoliquid phase of H 3PW 12O 40 is in a low-activity state absorbing excessive amounts of molecule.

Influence of the Isobutene/Methanol Ratio and of the Methyl tert-Butyl Ether Content on the Reaction Rate of the Synthesis of Methyl tert-Butyl Ether

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTInfluence of the Isobutene/Methanol Ratio and of the Methyl tert-Butyl Ether Content on the Reaction Rate of the Synthesis of Methyl tert-Butyl EtherHenk-Jan Panneman and Antonie A. C. M. BeenackersCite this: Ind. Eng. Chem. Res. 1995, 34, 11, 3817–3825Publication Date (Print):November 1, 1995Publication History Published online1 May 2002Published inissue 1 November 1995https://doi.org/10.1021/ie00038a019RIGHTS & PERMISSIONSArticle Views299Altmetric-Citations10LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (1 MB) Get e-Alerts Get e-Alerts

An experimental study on the application of polymer membranes to the catalytic decomposition of MTBE (methyl tert.-butyl ether)

In this experimental study, the methyl tert.-butyl ether (MTBE) decomposition was carried out in various inert membrane reactors composed of H 3PW 2O 40 and a polymer membrane. Polycarbonate (PC), polyarylate (PA) and cellulose acetate (CA) membranes were used in the membrane reactor. It was revealed that all the tested polymer membranes showed larger permeability of methanol than that of either MTBE or isobutene, and the membrane reactor showed better performance than the corresponding fixed bed reactor. The perm-selectivity of methanol/MTBE was in the order of CA > PC > PA, and the permeation ratio of product/MTBE was in the order of CA > PA > PC. Among the membrane reactors tested CA membrane reactor showed the best performance. The enhanced performance of the membrane reactor was mainly due to the selective permeation of methanol that made a methanol-deficient phase suppressing MTBE synthesis reaction in the reversible reaction.

Kinetics and Effectiveness of Catalyst for Synthesis of Methyl tert-Butyl Ether in Catalytic Distillation

The macrokinetics and intrinsic kinetics were measured for synthesis of methyl tert-butyl ether (MTBE) within the catalyst bed packed in a special way in an industrialized catalytic distillation column. The corresponding kinetic equations for forward and backward reactions were obtained. The variation of total effectiveness factor of the catalyst considering the diffusion in the catalyst pocket and within a granule of catalyst with reaction temperature and diameter of the pocket was calculated from the results measured. It was indicated that the effect of the catalyst packed in this way could not be revealed under the present operation condition.

Integral Analysis of Methyl tert-Butyl Ether Synthesis Kinetics

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTIntegral Analysis of Methyl tert-Butyl Ether Synthesis KineticsTiejun Zhang and Ravindra DattaCite this: Ind. Eng. Chem. Res. 1995, 34, 3, 730–740Publication Date (Print):March 1, 1995Publication History Published online1 May 2002Published inissue 1 March 1995https://doi.org/10.1021/ie00042a004RIGHTS & PERMISSIONSArticle Views908Altmetric-Citations36LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (1 MB) Get e-Alerts Get e-Alerts

Single-pot synthesis of methyl tert-butyl ether from tert-butyl alcohol and methanol: dodecatungstophosphoric acid supported on clay as an efficient catalyst

The efficacy of various solid acid catalysts and exchanged clays in a single-pot synthesis of methyl tert-butyl ether (MTBE) from tert-butyl alcohol and methanol is investigated; dodecatungstophosphoric acid (HPA) supported on K-10 clay gives the best yield with highest selectivity for MTBE.

The role of by-products formation in methyl tert-butyl ether synthesis catalyzed by a macroporous acidic resin

The effect of temperature and of the initial molar methanol-isobutene ratio on by-products formation in methyl tert-butyl ether synthesis catalyzed by a macroporous acidic resin were determined. The presence of dimethyl ether, methyl sec-butyl ether and diisobutene was studied in the temperature range 50–82°C, using an initial molar methanol-isobutene ratio ranging from 1.0 to 3.5. The byproducts formation was favoured by high temperatures. A low initial molar methanol-isobutene ratio favoured methyl sec-butyl ether and diisobutene formation, whereas high molar ratios favoured dimethyl ether formation. Results were explained by reaction mechanisms and compared with literature data.

MTBE synthesis catalysed by acid ion exchange resins: Kinetic studies and modeling of multiphase batch reactors

The kinetics for the liquid phase synthesis of methyl tert-butyl ether (MTBE) from isobutene and methanol using Amberlyst 18 (A18) ion exchange resin as catalyst was experimentally determined in a batch reactor in the temperature range 323–338 K and pressure range 0.8–1.0 MPa. Only methanol and MTBE are sorbed on the active acid sites. The reversible surface reaction on the pore walls and within the gel phase of the microparticles is the rate controlling step; the forward reaction is first order in isobutene and sorbed methanol and the reverse reaction is first order in sorbed MTBE. The experimental results can be described by a two parameter model based on a Rideal-Eley rate expression in liquid phase concentrations; the parameters are the forward reaction rate constant, kar, and the ratio between adsorption/desorption equilibrium constants of MTBE and methanol, D. The reactor model involved mass balances in both the gas and bulk liquid as well as in the macropores and microparticles and also energy balances in the catalyst particle and liquid phase. The activation energy was determined to be 130.2 kJ/mol.

Synthesis of Methyl tert-Butyl Ether Catalyzed by Dawson-Type Heteropolyacid.

Dawson-type heteropolyacid (H6P2W18O62) was found to be much more active for gas-phase synthesis of methyl tert-butyl ether (MTBE) from 2-methylpropene and methanol than Keggin-type heteropolyacids as well as SO42-/ZrO2, SiO2-Al2O3 and H-ZSM-5. By supporting H6P2W18O62 on SiO2, the yield of MTBE increased greatly and became comparable to that for Amberlyst 15.

Methyl tert-butyl ether decomposition over heteropoly acid catalyst in a cellulose acetate membrane reactor

In this study the methyl tert-butyl ether (MTBE) decomposition over H3PW12O40 was carried out in a cellulose acetate membrane reactor. The permeability of methanol through the cellulose acetate membrane was about 30 and 300 times higher than that of either isobutene or MTBE, respectively. The isobutene selectivity in the fixed bed reactor was only slightly higher than the methanol selectivity due to the side reaction. In the cellulose acetate membrane reactor, however, the isobutene selectivity in the rejected stream was 68% and the methanol selectivity in the permeated stream was up to 97%. The MTBE conversion in the membrane reactor was about 7% higher than that in the membrane-free fixed bed reactor under the same reaction conditions. The enhanced performance of the membrane reactor in this reversible reaction was mainly due to the selective permeation of methanol which resulted in a methanol-deficient condition suppressing MTBE synthesis reaction.

Multiple steady states during reactive distillation of methyl tert-butyl ether

This paper presents results of computer simulations of the synthesis of methyl tert-butyl ether (MTBE) in a fixed-bed reactor and in a reactive distillation column. These calculations clearly showed the advantages of MTBE synthesis in a catalytic distillation tower. Furthermore, the computer simulations showed that multiple steady states may occur in the reactive distillation column during MTBE synthesis in a broad range of operating conditions. An analysis of some sensitivity studies is presented.

Correlation and prediction of the vapor-liquid equilibria of the binary and ternary systems involved in MTBE synthesis

Vetere A., Miracca I. and Cianci F., 1993. Correlation and prediction of vapor-liquid equilibria of the binary and ternary systems involved in MTBE synthesis. Fluid Phase Equilibria 90: 189-203 The possibility of correlating and predicting the vapor-liquid equilibria of the binary and ternary systems formed by isobutene, methyl- tert-butyl ether (MTBE) and methanol has been considered. The predictive work is based on three methods: (i) Tassios' method, which requires only a limiting activity coefficient determined by gas chromatography for each binary system; (ii) the UNIFAC method, based on the application of the group contribution concept and (iii) Vetere's method, which hinges only on the pure component properties. The literature for the binary systems isobutene/methanol and MTBE/methanol have been correlated using the NRTL equation or predicted according to the above procedures. The ternary system of isobutene/MTBE/methanol has been studied at three temperatures using an experimental procedure which avoids the analysis of both phases at the equilibrium. A comparison is reported between the experimental and the predicted equilibrium data in order to evaluate the reliability of the three prediction methods.

Characterization of multicomponent diffusion effects in MTBE synthesis

The application of multicomponent diffusion theory to characterize intracatalyst mass-transfer resistances in the liquid-phase synthesis of methyl tert-butyl ether using acidic ion exchange resins, is discussed. By formulation of invariant solutions to the multicomponent conservation equation the system of coupled differential equations is reduced to a single ordinary differential equation and solved using orthogonal collocation. The parameters characterizing the invariant solutions are shown to yield significant insight into the nature of the diffusion proceses and illustrate the importance of accounting for multicomponent diffusion effects. A comparison between model predictions and published experimental data indicates good agreement between model and experiment in the limit where diffusion of methanol is rate limiting

Multiple solutions in reactive distillation for methyl tert-butyl ether synthesis

A reactive distillation column for the synthesis of methyl tert-butyl ether (MTBE) is simulated using a steady-state equilibrium stage model. For identical column and feed specifications, two distinctly different composition profiles are obtained, which correspond to high and low conversion of isobutene. With the aid of residue curve maps for simultaneous physical and chemical equilibrium, it is shown that the high- and low-conversion steady-state composition profiles obtained in the column simulations correspond to residue curves which have their starting points in distinctly different composition regions

Effect of water presence on methyl tert-butyl ether and ethyl tert-butyl ether liquid-phase syntheses

Equilibrium constants for the liquid-phase synthesis of methyl tert-butyl ether (MTBE) and ethyl tert-butyl ether (ETBE) were determined experimentally in the temperature range 40-80 C, using an initial water percentage range in the alcohol of 1.4-5 wt%. The initial molar alcohol-isobutylene ratio varied from 0.8 to 1.44. Both systems behave nonideally, and the equilibrium constants found agree with those determined without initial water quoted in the literature. In experimental kinetic runs performed at 40 C, ETBE and MTBE production rates are strongly lowered by the initial water presence. This inhibitor effect disappears as water is converted into tert-butyl alcohol (TBA). The TBA equilibrium is reached faster than those of the ethers, and the residual water is rather small.

Liquid-phase synthesis of methyl tert-butyl ether on heterogeneous heteropoly acid catalyst.

The liquid-phase synthesis of methyl tert-butyl ether (MTBE) by the reaction between methanol and tert-butyl alcohol with several heteropoly acid catalysts was studied. Among the catalysts tested, acidic cesium salts of 12-tungstophosphoric acid and 12-tungstosilicic acid showed high activities and selectivities for the production of MTBE. The origin of high activity and selectivity of cesium heteropoly acids was discussed from kinetic viewpoints.

Equilibrium constants for methyl tert-butyl ether liquid-phase synthesis

Equilibrium constants for the liquid-phase synthesis of methyl tert-butyl ether (MTBE) were determined experimentally in the temperature range 40-80 o C. Equilibrium was established in the methanol addition to isobutylene for obtaining MTBE over the sulfonic acid resin Lewatit SPC 118 as the catalyst in a batch reactor maintained at 1.6 MPa. The experimental equilibrium constant is given as a function of temperature, and enthalpy, free energy, and entropy changes have been determined as well

Developments in the production of methyl tert-butyl ether

The catalysis of the etherification of alcohol and iso-olefin mixtures is discussed. Emphasis is placed on the synthesis of MTBE (methyl tert-butyl ether), but mention is also made of other ethers such as ETBE (ethyl tert-butyl ether), SAME ( sec-amyl methyl ether) and MIPE (methyl isopropyl ether) and, to a very limited extent, of hydrocarbon feedstocks other than iso-olefins. Established sulphonated resin catalysts are described together with various aspects of their catalytic characteristics, including kinetics, thermodynamics and the occurrence of side-reactions. The use of alternative inorganic adds, especially zeolites, is covered and comparisons drawn between these systems and the ion-exchange resins. Finally, attention is given to the design of commercial processes for the production of MTBE.

Layered Group(IV) Metal Phosphates as Catalysts for MTBE Synthesis

Layered group(IV) metal phosphates and their phenylsulfonic acid derivatives were used as catalysts for the synthesis of methyl tert-butyl ether (MTBE) from methanol and isobutene. Because zirconium and titanium phosphates have only moderate acidic strength, relatively high temperatures are required to activate their Bronsted acidic sites. The optimal activity was obtained at ca. 443 K. Their phenylsulfonic acid derivatives, however, demonstrated higher acidic strength by giving much higher activity toward MTBE formation at relatively low temperaures. The catalysts were characterized in terms of their structure, thermal stability, surface area and acidic strength.